Mammals

TigerKangarooRabbit Monkey
Polar Bear
This is an article http://articles.sfgate.com/2008-03-02/travel/17166361_1_wild-monkeys-macaques-national-park
Video 1: Panda
http://video.nationalgeographic.com/video/player/
Video 2: Kangaroo
http://video.nationalgeographic.com/video/player/
Mammal Stats

• Mammals are approximatley 0.3% of all living things on earth
• Found in range of environments because they are endothermic and have diverse body plans
• Dominant animal living in current era
• Over 4,000 species
  • Smallest: hog nosed bat/shrew
  • Largest: Blue whale

Mammal Characteristics

• Body structure
  • Body covered by hair
  • Specialized teeth for different diets
    • Canines: tearing
    • Incisors: cutting
    • Molars: grinding (especially plants; herbavores)
  • Range of foot structures
    • Walk on foot, digits, or one toe (Ex. Hoof)
• Body Function
  • Lungs, diaphragm
  • Four chambered heart
  • Endothermy
• Reproduction
  • Internal fertilization
  • Internal development in uterus
    • Nourishment through placenta
  • Mammary glands supply milk
  • Most give birth to live young

Mammal Classification

• Mammals placed into 3 orders determined by reproductive methods

1. Monotremes

• Egg laying mammals
• Lack placenta
• Ex. Duck billed platypus and Echidna (spiny anteater)

2. Marsupials

• Pouched mammals
• Found mainly in Australlia and New Guinea
• Kangaroos, opossums
• Short gestation period

3. Placental Mammals

• Yound develop completley in uterus
• Nourished by the placenta
• Gestation: period of development inside the mother- 9 months
  • Much longer gestation period than other mammals
• 95% of all mammals